Nutrition
Underfeeding Beef Cows has Consequences
By North Dakota State University extension
Beef cows that have been underfed
during gestation and lactation will be less
productive than cows fed adequate diets.
“For adequate production, a beef cow’s daily
ration must meet nutritional requirements,”
says Karl Hoppe, North Dakota State University
Extension livestock systems specialist at the
Carrington Research Extension Center. “Cows
will lose body weight when consuming less
energy than needed for maintaining body
functions and production demands.”
Extreme cold temperatures or wind chills will
increase the cow’s energy needs substantially.
If the cow doesn’t receive additional energy
through her diet, she will take nutrients from
her body to meet her energy demands.
Production problems will occur when the cow
loses too much weight. However, a heavier cow
will be able to lose more weight than a thin cow
before serious production problems occur.
A visual method for determining weight loss or
gain in beef cows is body condition scoring (BCS).
Beef cows that carry more condition (or fat) will
rate a higher body condition score (maximum
of BCS 9) than thin cows (minimum of BCS 1).
A body condition score of 4 is borderline for
maintaining adequate production in beef cows.
Thin Cows Take Longer to Rebreed
“Cows with a body condition score of 4 or
less at calving will have poor reproductive
performance,” says John Dhuyvetter, NDSU
Extension livestock systems specialist at the North
Central Research Extension Center near Minot.
After calving, thin cows will require more days to
reach first estrus (heat) and more days to become
pregnant. Researchers report that cows with
a borderline or lower BCS need an average of
12 more days to reach first estrus. For example,
they found that cows with a BCS of 4 or less
needed 61 days while cows with a BCS of 5 or
greater needed 49 days to reach first estrus.
Changing Body Condition Scores in Borderline (BCS 4) Cows After Calving
Condition Score Change
< 0 0 to 1 1 to 2 > 2
Average BCS change - 0.41 0.49 1.22 2.44
Days of pregnancy 150.9 126.7 106.3 98.8
Milk production (lb./day, day 60) 11.2 13.2 14.5 15.4
Source: NDSU Extension
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